Revisions of history, in the absence of critical thinking, are a dangerous things. I stand by my original comments and look forward to Foss Leach's reply after reading the reference cited in the earlier posting.
Foss Leach wrote:
There is no direct evidence that any Polynesians (including Maori) deliberately set out to improve the fertility of dryland soils by adding things such as charcoal...
Your comments are not supported by the archaeological literature. The critical paper, very kindly pointed out to me by Owen Wilkes, and completely missed in the recent DOC "Maori gardening" publication is : McNabb. J. W. Sweet potatoes and Maori terraces in the Wellington area. J. Polynesian Society. 1969 78: 83-111
This has a superb review of kumara production in Aotearoa, including clear evidence that 100's of acres in Waimea and the Waikato was systematically altered with charcoal, up to 40cm deep in the soil.
It is often the assumptions we make about "primitive" cultures that blinker us so that we miss the obvious, both archaeologically and rationally.
Yes, a very, very good point. Kumara was one of the foods of chiefs. Karaka may well have been another. As such, most records show that the kumara brought to Aotearoa by Maori were tended as individual plants.
In the Amazonia, a lot of the beneficial charcoal effect seems to have come from the addition of animal fertiliser. No big mammal poopies in Aotearoa!! But what there was was cooking juice infused charcoal (new charcoal and probably under pressure!) I am sure that someone would have noticed very early on (if the knowledge wasn't brought from umu cooking in Hawaiki) that these charcoals made plants grow really well.
... could anyone confirm some anecdotal info I had lately - Hemp biomass is highest in cellulose, as well as an excellent nitrogen-fixer. Grows like a weed.
And if this is correct, why aren't we growing more of it?
While I love universal panaceas, hemp is not a nitrogen fixer...
One of the really important things, well borne out by our own experiments as well as other results presented at the IAI, is that indigenous use of biomass was site specific. Soils do vary and the soils in Brazil and Japan where the biggest effects have been seen are what are known as soils of variable charge which will ring some bells for those who know anything about andasols and their distribution in Aoteaoa/New Zealand! Indigenous people used any local material that was effective in growing plants better. Indigenous people in Brazil used pottery chards in some instances. Maori in the Waikato used pumice sand. Now there is a challenge for you thinkers out there. I'll give you a week to think about it!!
Jo S wrote:
Do you know if Aotearoa biocarbon are actually looking at liscencing the flash-burner from UH to make carbon for agriculture?
Yes, licensing is one option we are investigating at Aotearoa Biocarbon.